The invention relates to a filtering device for separating liquid and solid material from a mixture, provided with an endless filter belt, means for supplying the mixture for separating on the upper side of the filter belt and a suction box on the underside of the filter belt connected toga pump.
Such a filtering device is known from EP-A-92201151.5.
Such a filtering device can only be used for filtering particular mixtures. Mixtures including a substance which at ambient temperature and atmospheric pressure can pass into a gaseous phase cannot be separated with such a filtering device.
It is the object of the invention to provide a filtering device which makes this possible.
This is achieved according to the invention in that the operative components of the filtering device are placed in a pressure chamber, a higher than atmospheric pressure is maintained in the pressure chamber and the difference in the pressure in the chamber and the pressure in the suction box is relatively small.
By placing the mixture for separating under a higher pressure than the lowest evaporation pressure applying to any of the components in the mixture at the prevailing temperature, the danger of any of the substances passing into the gas phase is obviated.
It is noted that a filtering device is known from EP-A-0 033 371 wherein the whole installation is accommodated in a high pressure chamber accessible to service personnel.
Only a limited overpressure can be applied with such an installation. When higher pressures are used the space is no longer accessible to personnel without very special precautionary measures.